Knitting machines with air feed

ABSTRACT

The knitting machine ( 1 ) according to the invention is provided with an air-conducting device ( 21 ) for conducting air into an air guidance space ( 18 ) that is embodied between the cam assembly ( 12 ) and the knitting cylinder ( 3 ). As a result of this air guidance space, cleaning air is supplied directly to the knitting tools ( 5 ), without requiring an outer casing around the cam assembly. In the same way, the air can also be guided between a dial and its associated cam assembly to corresponding dial needles or sinkers.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority of German Patent Application No. 10 2005 057 354.1, filed on Dec. 1, 2005, the subject matter of which, in its entirety, is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to a knitting machine where air is supplied to the knitting tools.

Knitting machines generally comprise a larger number of knitting tools, which are moved back and forth with the aid of suitable driving mechanisms to form a knitted fabric from guided threads. In the process, dust and thread residues can collect on the knitting tools, which can interfere with the knitting process.

Document U.S. Pat. No. 5,737,942 discloses a circular knitting machine with a needle cylinder provided with a plurality of needle slots on the outside. Latch needles that are respectively provided with a butt are positioned inside of these slots. The butts of the latch needles project from the needle slots and are connected to form a cam assembly comprising a plurality of cams. During the rotation of the needle cylinder, the butts of the needles follow the contour of the individual cams, so that the needle hooks are correspondingly moved up and down.

The cam assembly is provided with a ring-shaped casing on the outside, through which filtered air is supplied by means of a fan. This outer casing together with the upper edge of the needle cylinder and/or a sinker plate forms a substantially ring-shaped channel through which air is blown onto the moving parts, for example the needle hooks.

Since the complete cam assembly must be encased to generate the cleaning air stream, access to the cams is made more difficult. The casing must be removed for any adjustment operations to the cams, at least in part, in order to provide access to the respective cam. In addition, only the hooks of the knitting tools, meaning their working parts, are blown clean with the known concept. No further cleaning effect is achieved.

Starting with this problem definition, it is the object of the present invention to create a knitting machine that overcomes these disadvantages.

SUMMARY OF THE INVENTION

This object is solved with the knitting machine as disclosed in claim 1:

The knitting machine according to the invention is provided with an air-conveying device, which feeds air into an air guidance space embodied between the cam assembly and the needle bed, wherein the needle bed can be the round knitting cylinder of a circular knitting machine, for example, or also its dial. In those cases, the needle bed (knitting cylinder or dial) is moved while the cam assembly remains stationary.

The air guidance space can be a more or less large gap between the cam assembly and the needle bed. In addition, the needle slots contribute considerably to the flow cross section of the air guidance space. Even if the otherwise existing gap between needle bed and cam assembly is reduced to nearly zero, considerable amounts of air can still flow through the needle slots which are not completely filled by the knitting tools. The knitting tools furthermore can be provided with airflow channels for reducing the flow resistance of the air in the needle slots. Finally, the cams themselves can have considerable flow cross-sections, which contribute to the air guidance space.

The air feed guidance between needle bed and cam assembly permits a targeted conducting of the air stream to the working parts of the knitting tools, meaning to the hooks and tongues of the respective needles. This is achieved without having to encase the cam assembly, thus permitting unrestricted access to the cams from the outside, without having to remove air guidance hoods or the like.

The guidance of the cleaning air stream in the space existing between the cam assembly and the needle bed furthermore permits not only the cleaning of the working parts of the knitting tools, but also the cleaning of the knitting tools and the needle slots. In particular, abraded material and dust which enters the cam region or which forms therein can be removed from the needle slots and the cams. The air guidance concept according to the invention consequently contributes to an improved operating safety and to reducing the wear and tear on the knitting machine. The cam region and the needle bed, meaning the needle cylinder, in particular can be kept free of abrasive particles.

The concept according to the invention can also be used for other knitting tools, for example sinkers, welt hooks or transfer needles, compound needles, or the like. In all of these cases, the air stream used for blowing off the knitting tools is guided completely if possible through the space between the knitting and/or sinker cams and the cylinder and/or the needle bed. In the ideal case, this applies to the total air stream used for cleaning.

The cam assembly normally consists of cams or cam segments, which are arranged on a cam base plate. In the case of a circular knitting machine, this cam base plate is ring-shaped and can consist of individual segments arranged one beside the other, wherein the cam segments adjoin with their narrow sides. Sealing means are provided between the cam segments of a preferred embodiment, so as to seal the cam segments against each other, wherein this measure reduces air losses. A suitable cover between the upper edge of the cam segment and the sinker ring can furthermore close off this air exit opening to conduct the cleaning air stream without losses into the stitch-forming region. However, air exit openings can also be purposely provided to allow the exit of a partial stream of the cleaning air. This measure can serve to purposely remove abrasion particles generated in the cam region of the cam assembly, without allowing the abrasive particles to reach the working parts of the knitting tools. For this purpose, it may be sufficient to omit the sealing means between two or more cam segments.

The air-conducting device is preferably a fan, which blows accelerated air into the air guidance space. The fan can be embodied as a separate unit, which sucks in air from the environment, filters the air and conveys it to the air guidance space in the knitting machine. In that case, the air-conducting device has a drive that is separate from the knitting machine drive. The advantage of this solution is that the amount of conducted air can be adjusted independent of the operating speed of the knitting machine.

The fan can alternatively also be integrated into the knitting machine, which in many cases is desirable because of the increased simplicity. The fan is then embodied in the form of at least one air blade. In most cases though it is useful to have several air blades that are distributed, for example, over the circumference of the needle cylinder of a circular knitting machine. The air blades are arranged below the segments of the cam assembly (meaning on the side facing away from the working parts of the knitting machine) and serve to conduct the sucked-in air upward and through the air guidance space to the working parts of the knitting tools. The air flows in the process through the intermediate space between the cams and the needle cylinder, thereby keeping this intermediate space clean as well. The air can be sucked in through a channel, which extends below the cam base plate. The suction channel can be provided with a filter to clean the sucked in air before it is blown in particular into the cam region.

Different modifications of the invention can distinguish themselves by a cleaning device that is designed, for example, to clean from time to time the filters connected to the suction channel. The cleaning device can be a separate fan, which blows a stream of air into the activated suction channel, thereby operating the filters in the opposite direction and blowing away dust clinging to the outside.

It is furthermore considered advantageous if the filters are embodied as individual segments, for example in the form of a ring of individually replaceable segments that are arranged on the outside of the cam base plate.

In addition or as an alternative, lubricating fluid can also be added to the air stream to supply the knitting tools and/or the cams with lubricant. The lubricant feed-in can be continuous or, if desired, only at times. A lubricating device can be provided for this, which adds lubricant to the air stream, for example before it reaches the cam assembly. The lubricant can be metered in through a controlled activation of the lubricating device.

Additional advantageous details of embodiments for the invention are the subject matter of the drawing, the specification, or the claims. In the drawing, the exemplary embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a vertical section through a detail of a knitting machine with internal fan.

FIG. 2 is a schematic representation of a vertical section through a detail of a knitting machine with external fan;

FIG. 3 illustrates the knitting machine according to FIG. 1, provided with a cleaning device.

FIG. 4 illustrates the knitting machine according to FIG. 2, provided with a lubricating device.

DETAILED DESCRIPTION OF THE INVENTION

A knitting machine is illustrated in FIG. 1 with the exemplary embodiment of a circular knitting machine. Its needle bed 2 takes the form of a knitting cylinder 3, provided on its outside with vertical needle slots 4, meaning these extend parallel to its rotational axis. Knitting tools 5 are arranged inside the needle slots 4, e.g. in the form of the latch-type needles 6 shown herein, which can be displaced in longitudinal direction of the respective needle slot 4. The latch needle 6 is provided on one end with a hook 7 that projects from the needle slot 4 and comprises a latch 8, positioned pivoting. The shaft of the latch needle 6 extends inside the needle slot 4 and has a butt 9, which functions to drive the latch needle 6.

While the knitting cylinder 3 rotates during the operation, a ring-shaped cam base plate 10 that encloses the cylinder from the outside remains stationary. The cam base plate 10 is provided with a cam assembly 12 on its substantially flat surface 11, which consists of a number of cams and/or cam segments 13. The cam assembly 12 thus encloses the knitting cylinder 3 in the manner of a ring. Its cam segments 13 define at least one, but preferably several, cam curves 14 in the form of cam surfaces, which cooperate with the butts 9 of the latch needles 6 to move these in a controlled manner if the knitting cylinder 3 rotates. The cam segments 13 are held in place with suitable fastening means 15, for example in the form of bolts 16 and locating pins 17 on the cam base plate 10.

An air guidance space 18 is formed between the needle cylinder 3 and the cam assembly 12, which also includes a gap 19 between the outside contour of the knitting cylinder 3 and the cam assembly 12. Also included in the air guidance space 18 are the needle slots 4, insofar as these are not occupied by the knitting tools 5 or are blocked, as well as clearance spaces and cavities in the cam segments 13.

An air-conducting device 20 is connected to the air guidance space 18, which for the exemplary embodiment according to FIG. 1 is formed by at least one, but preferably and usefully, a plurality of air blades 21. The air blades 21 are screwed approximately at the level of the cam base plate 10 o the outside circumference of the knitting cylinder 3, for example with the aid of fastening screws 22 in a ring-type arrangement, thereby forming a fan wheel. The air blades 21, for example, are arranged at an angle to the rotational axis of the knitting cylinder 3, so as to form an axial fan.

The cam base plate 10 with a recess defines together with the cam segments 13 a ring-shaped fan chamber 23 inside of which the air blades 21 move. The fan chamber 23 is provided with at least one, preferably a number of air flow-through openings 24, which empty out on the underside of the cam base plate 10, wherein these air flow-through openings 24 function as intake openings and can be provided directly with an air filter. For the exemplary embodiment shown in FIG. 1, however, a ring-shaped cover plate 25 is provided, which is positioned at a distance to and preferably parallel to the underside of the cam base plate 10 and together with this plate defines a gap-type, radially extending suction channel 26. This channel ends at the outside circumference of the cam base plate 10. An air filter 27 is provided at the preferably funnel-shaped expanding intake opening of the suction channel 26 in order to suction in and simultaneously clean air at a low speed. This filter is preferably segmented, meaning is consists of a rim-type arrangement of individual, for example rectangular or square, filter segments that can be replaced separately.

The individual cam segments 13 of the cam assembly 12 are positioned next to each other, essentially with the narrow sides 28. Radially extending gaps can therefore remain between the individual cam segments 13, through which a portion of the air stream escapes that is generated by the air-conducting device 20. In individual cases this may be desirable in order to move abrasion particles generated in the region of the cam assembly 12 toward the outside. However, as a rule it restricts the efficiency of the fan formed with the air blades 21, so that a sealing of the space between the cam segments is desired. A suitable sealing agent 29 can be used for this, e.g. in the form of a rubber cord 30, which extends from the top surface 11 to approximately the upper end of each cam segment 13. As indicated (31) with dashed lines in FIG. 1, it can extend to the knitting cylinder 3 to form the narrowest possible air exit opening for the cleaning air stream. Otherwise, the rubber cord 30 preferably extends approximately parallel to the knitting cylinder 3. Other suitable means agents can also be used in place of the rubber cord 30, such as lip seals, a sealing agent, or rubber profiles that are squeezed from the outside between the cam segments.

To direct the air stream controlled onto the working part 7 of a knitting tool 5, sealing means 44 can be provided between the cam assembly 12 and the sinker ring 32.

These sealing means are embodied in the form of suitable covers 45, e.g. sheet metal covers. These can take the form of a ring consisting of several parts or segments, which can be attached in a manner known per se to the cam segments 13 or the sinker ring 32. Suitable sealing means ensure the seal between the sinker ring 32 and the cam segments 13, so as to prevent the air stream from leaving this intermediate space.

Depending on the structural design of the knitting machine 1, additional devices can also be provided, such as a sinker ring 32 which rotates along with the knitting cylinder 3 and which carries the stitch-forming sinkers 33 that operate jointly with the knitting tools 5. Passages 34 are provided between the sinker ring 32 and the knitting cylinder 3, through which the fan-supplied air can flow to the hooks 7.

The knitting machine 1, described so far, operates as follows:

During the operation, the cam base plate 10 and the cam assembly 12 remain stationary, while the knitting cylinder 3 and the possibly existing sinker ring 32 with the knitting tools 5 and/or the sinkers 33 rotate. The kitting tools 5 and the sinkers 33 in the process carry out a vertical and/or horizontal back and forth movement. The air blades 21 rotate along with the knitting cylinder 3 and, owing to their geometry of having an outside edge that is positioned at an angle to the movement direction of the knitting tool 5, consequently generate an air stream that is directed upward in FIG. 1, meaning toward the cam assembly 12. This air stream flows through the air guidance space 18 between the cam assembly 12 and the knitting cylinder 3 and finally reaches the operating area of the knitting tools 5. In the process, the air stream cleans the area existing between the cam assembly 12 and the knitting cylinder 3 as well as the knitting tools 5 by blowing dust, pieces of filaments, thread residues, and similar material away from the needle slots 4 and the knitting tools 5. The air needed for this is suctioned in by the fan with the aid of air blades 21, via the suction channel 26 and through the air filter 27.

The knitting machine 1 embodiment, described so far, can be subject to modifications. For example, the cam base plate 10 can be formed with a plurality of successively lined-up individual segments, wherein each segment of the cam base plate 10 in circumferential direction must have the same size as a cam segment 13. Each segment of the cam base plate 10 in that case can be provided with a separate air filter.

FIG. 2 furthermore shows that a separate fan 36 can be provided, which conveys air to the suction channel 26 by means of a hose 36. In that case, the fan usually formed with the air blades 21 can be omitted. The air guidance space 18 in that case is again supplied with an air stream via the fan 35, which is conveyed independent of the speed and rotational direction of the knitting cylinder 3 to the knitting tools 5, wherein the air filter 27 is arranged on the fan 35. Otherwise, the description provided for the exemplary embodiment shown in FIG. 1 also applies, using the reference numbers already introduced.

FIG. 3 illustrates a different modification of the knitting machine according to the invention as shown in FIG. 1. The fan for generating the air stream for the air guidance space 18 is again formed with air blades 21. The function corresponds insofar to the knitting machine 1 as shown in FIG. 1. However, an additional fan 37 is provided that operates at least for short periods and can be connected via one or several openings in the cover plate 25 to the suction channel 26. The fan 37 is normally inactive. If the fan is activated, it generates a slight overpressure inside the suction channel 26, which causes the air to be blown through the air filter 27 toward the outside, wherein this air stream can be used to clean the filter 27 if necessary. The fan 37 can be an integral part of the knitting machine 1, or it can be a separate fan, which is manually carried or driven from machine to machine and is connected thereto. The opening 38 for connecting the fan 37 remains closed if not in use.

Alternatively, it is possible to use a separate suctioning device to suction off the filter 27 from the outside for removing loosely adhering dust or lint. The fan 37 forms a cleaning device 39 for the filter 27.

FIG. 4 illustrates a different embodiment of the knitting machine 1, which is based on the variant according to FIG. 2. A lubricating device 40 is additionally provided for carrying lubricating agents into the knitting machine 1 along with the air stream flowing through the air guidance space 18. This can take place continuously or from time to time, as needed. The lubricating device 40 comprises a pump 41 for pumping the lubricant, a lubricant supply 42, and at least one dispenser or nozzle 43 for dispensing lubricants into the suction channel 26 or also to another suitable location through which the air stream flows which is generated by the fan 37. Several nozzles 43, for example, can be disposed along the circumference of the knitting cylinder 3 and can be activated, as needed, either simultaneously or one after another to dispense lubricating agents over a longer or shorter period of time. The lubricant is preferably atomized into small droplets by suing a suitable design of the nozzle 43.

It is furthermore possible to add the lubricant to the air conducted by the fan 37, wherein the consistency of the lubricant must be selected such that the danger of leaving oily deposits in the hose 36 is for the most part prevented. It is also possible to install the lubricant supply closer to the needle slots 4 and/or the cam assembly 12, which can be achieved by moving the nozzle 43 to the region near the segments 13.

The lubricating device 40 can also be combined with the knitting machine according to FIG. 1 or FIG. 3, wherein the nozzle 43 can then be arranged as for the exemplary embodiment shown in FIG. 4, for example, such that it sprays into the air intake opening 24.

The knitting machine 1 according to the invention is provided with an air-conducting device 21, 35, 37 for blowing air into an air guidance space 18, embodied between the cam assembly 12 and the knitting cylinder 3. The air for cleaning is supplied via this air guidance space directly to the knitting tools 5, without requiring an outer casing for the cam assembly. In the same way, the air can also be guided between a dial and the associated cam to the corresponding dial needles or sinkers.

REFERENCE NUMBER LIST

-   1 knitting machine -   2 needle bed -   3 knitting cylinder -   4 needle slots -   5 knitting tools -   6 latch needle -   7 hooks, working part -   8 latch -   9 butt -   10 cam base plate -   11 top surface -   12 cam assembly -   13 cam, cam segment -   14 cam curves -   15 fastening means -   16 bolts -   17 locating pin -   18 air guidance space -   19 gap -   20 air conducting device -   21 air blades -   22 screws -   23 fan chamber -   24 air flow-through openings -   25 cover plate -   26 suction channel -   27 air filter -   28 narrow sides -   29 sealing means -   30 rubber cord -   31 dashed line (for rubber cord) -   32 sinker ring -   33 sinkers -   34 channels -   35 fan -   36 hose -   37 fan -   38 opening p0 39 cleaning device -   40 lubricating device -   41 pump -   42 lubricant supply -   43 nozzle -   44 sealing means -   45 cover 

1. A knitting machine (1) with a needle bed (2) provided with a number of slots (4) for accommodating knitting tools (5), with a number of knitting tools (5) which are arranged displaceable in longitudinal direction inside the slots (4) of the needle bed (2) and are provided with a working part (7), with a cam assembly (12) for driving the knitting tools (5), which is arranged adjacent to the needle bed (2), so that at least one air guidance space (18) is defined between the needle bed (2) and the cam assembly (12), and with an air-conducting device (21, 25, 37) that is connected to the air guidance space (18) for guiding an air stream through this space and onto the working part (7).
 2. The knitting machine according to claim 1, characterized in that the needle bed (2) is a knitting cylinder (3) of a circular knitting machine.
 3. The knitting machine according to claim 1, characterized in that the needle bed (2) is a dial of a circular knitting machine.
 4. The knitting machine according to claim 1, characterized in that the knitting tool (5) is a knitting needle (6).
 5. The knitting machine according to claim 1, characterized in that the knitting tool (5) is a sinker (33).
 6. The knitting machine according to claim 1, characterized in that the cam assembly (12) comprises cam segments (13), which are sealed against each other.
 7. The knitting machine according to claim 6, characterized in that a sealing means (29) is arranged between the cam segments (13).
 8. The knitting machine according to claim 1, characterized in that the air-conveying device (21, 35, 37) is a fan.
 9. The knitting machine according to claim 8, characterized in that the fan (37) is provided with a separate drive.
 10. The knitting machine according to claim 8, characterized in that the fan (35, 37) is embodied as a separate unit, which is connected to the knitting machine (1) via at least one air hose (36).
 11. The knitting machine according to claim 8, characterized in that the air-conducting device (20) comprises at least one air blade (21), which is connected to the knitting cylinder (3) of the knitting machine (1).
 12. The knitting machine according to claim 8, characterized in that the air-conducting device (20) comprises at least one air blade (21), which is connected to the dial (32) of the knitting machine (1).
 13. The knitting machine according to claim 12, characterized in that several air blades (21) are provided, which form an air blade ring.
 14. The knitting machine according to claim 1, characterized in that the air-conducting device (20) is connected to a suction channel (26) that extends through a portion of the knitting machine (1).
 15. The knitting machine according to claim 14, characterized in that the suction channel (26) is embodied below a cam base plate (10), which supports the cam assembly (12).
 16. The knitting machine according to claim 14, characterized in that the suction channel (26) extends in radial direction, relative to the knitting cylinder (3).
 17. The knitting machine according to claim 14, characterized in that the suction channel (26) is provided with a filter (27) at the intake opening.
 18. The knitting machine according to claim 17, characterized in that a cleaning device (39) is assigned to the filter (27).
 19. The knitting machine according to claim 1, characterized in that a lubricating device (40) is provided for adding lubricating agent to the air stream.
 20. The knitting machine according to claim 11, wherein several air blades (21) are provided, which form an air blade ring. 